Validity Evidence for the Nursing Diagnosis "Ineffective Lymphedema Self-Management" in Women who Underwent Mastectomy.

Aim: To verify the evidence of content validity of the nursing diagnosis "Ineffective Lymphedema Self-Management" in women who underwent mastectomy. Design: Methodological study of content validation by expert judges. Method: Content validation was conducted between July and October 2023 through a semi-structured online questionnaire sent to 80 expert judges, of whom 52 participated. The study was approved by the Research Ethics Committee (CAAE No. 63063922.0.0000.5078). Elements identified in a preceding concept analysis were evaluated for relevance using Aiken's V coefficient (V ≥ 0.90) with 95% confidence intervals. Cronbach's alpha was used to assess internal consistency. The sample size (n = 47) was determined using a precision estimation formula for content validity indices. Results: Of the 47 terms submitted for evaluation, 31 were considered valid as defining characteristics and related factors. The terms "psychological and cognitive limitations" and "patients who underwent a mastectomy" were validated for associated conditions and at-risk population, respectively. Expert judges suggested the inclusion of "female breast cancer survivors," "access to health services," and "lack of medical information." Cronbach's alpha was 0.97 (95% CI: 0.96-0.98). Conclusion: The nursing diagnosis "Ineffective Lymphedema Self-Management" was partially validated. New elements were identified that may elevate the evidence level of this diagnosis and refine its applicability in clinical practice. Implications for Nursing Practice: The validated elements provide nurses with a structured framework for identifying and managing lymphedema in women who underwent mastectomy, contributing to early detection and targeted interventions.